Compressor



Sept. 28, 1965 4c. E. BoETTcHER COMPRESSOR 2 sheets-sheet 1 Filed July19. 1963 I :lumix i* Sept. Z8, 1965 c. E. BoET-rcHER COMPRESSOR FiledJuly 19, 1963 SufC.

United States Patent O 3,208,667 'COMPRESSOR Carl E. Boettcher,Evansville, Ind., assignor to Whirlpool Corporation, a corporation ofDelaware Filed July 19, 1963, Ser. No. 296,301 11 Claims. (Cl. 23o-207)This invention relates to compressors and in particular to compressorsfor refrigeration systems.

In one form of conventional refrigeration system, refrigerant vapor isdelivered from an evaporator to a compressor which compresses the vaporfor delivery to a condenser. Thus, the inlet to the compressor is at arelatively low pressure and the outlet from the cornpressor is at arelatively high pressure. One form consists of a compressor with ahighpressure crankcase in which the space within the housing surrounding theworking parts is carried at substantially condenser pres- Usuallysuction vapor entering the compressor passes directly intoi thecompression chamber.

Several problems arise in such compressor structures: Firstly, liquidinthe refrigerant vapor delivered to the compressor causesshock loads onthe bearings of the compressor and undesirable noise particularly atstart up. Further, such compressors require the use of precoolers formotor cooling. Still further, in such compressors, entrainment oflubricating oil in the refrigerant vapor passing through the precoolerand in turn passing 'against the motor of the compressor has adeleterious effect on some motor insulation materials. Additionally,more efficient performance is obtained if a `means is provided forremoving a portion of the heat of compression.

The present invention comprehends an improved rotary compressor whicheffectively eliminates the above-discussed problems in a novel andsimple manner. Thus, a principal feature of the present invention is theprovision of a new and improved rotary compressor.

Another feature of .the invention is the provision of such a rotarycompressor having new and improved means for separating liquid such aslubricating oil from the incoming refrigerant vapor.

A further feature of the invention is the provision of such a rotarycompressor hav-ing new and improved means for cooling the lubricatingoil thereof.

A yet further feature of the invention is the provision of such a rotarycompressor'having a simplified construction wherein an inlet chamber isprovided surrounding the oil sump of the compressor thereby placing theincoming refrigerant vapor in heat transfer association with the oil.

Another feature ofthe invention is the provision of such a rotarycompressor including a housing defining a chamber including a portiondefining a pressure space including a lubricating oil sump, means in thechamber for compressing refrigerant gas, wall means adjacent the sumpportion of the housing defining a fiow passage between the wall meansand the housing, means for conducting refrigerant gas to the ow passagefor cooling the sum-p, and means for conducting the refrigerant gas fromthe flow passage to the,A chamber for compression therein by thecompressing means.

A further feature of the invention is the provision of such a rotarycompressor having improved means for delivering to the compressorchamber oil removed from the refrigerant vapor at the inlet, therebyeffectively bypassing the motorA chamber portion of the compressor.

Other features and advantages of the invention will be apparent fromtheu following description taken in connection with the accompanyingdrawings wherein:

FIGURE 1 is a fragmentary diametric section ofa compressor embodying theinvention;

FIGURE 2 is a fragmentary enlarged vertical section .thereof takensubstantially along the line 2 2 of FIG- URE 3;

FIGURE 3 is a transverse section taken substantially along the line 3--3of FIGURE 1;and

FIGURE 4 is a fragmentary vertical section taken substantially along theline 4-4 of FIGURE 3.

In the exemplary embodiment of the invention as disclosed in thedrawing, a compressor generally designated 10 is shown to comprise ahousing generally designated 11 including an upper, downwardly openingcup-shaped member 12, a first lower, upwardly opening cup-shaped member13, and a second lower, upwardly opening cupshaped member 14 nestedwithin member 13 to define therebetween an inlet chamber 15. Acompressor apparatus generally designated 16 is disposed within thehousing 11 and includes a motor 17, a front head 18, a cylinder 19 inwhich is disposed a rotor 20, and a rear'head 21, the motor and rotorbeing mounted on a common shaft 22 coax-ially vertically disposed withinthe housing l1. The front head 18 carries an annular sealing ring 23which seals the front head to the housing member 14, thereby dividingthe interior of the housing into an upper suction chamber 24 and a lowerpressure chamber 25. The lower portion 26 of the housing member 14defines a sump for holding a body of lubricating oil 27.

As shown in FIGURE 4, refrigerant vapor is delivered from therefrigerant system evaporator (not shown) to the chamber 15 through aninlet fitting 28 having a suitable filter screen 29 installed therein.Liquid, such as lubricating oil, entrained in the refrigerant vapordrops therefrom in chamber 15 and is collected at the bottom of thechamber as a body of liquid 30, as shown in FIG- URES 1 and 4. As bestshown in FIGURE 1, the inner housing member 14 is spaced upwardly fromthe bottom wall 31 of the outer housing member 13 by means of aplurality of depending lugs 32 to permit the passage of the collectedliquid downwardly to the bottom of the chamber 15. o

The refrigerant vapor in chamber 15 is in effective thermal transferassociation through housing portion 26 with the lubricating oil 27 inthe sump, thereby effectively cooling the oil. Conversely, heat transferfrom the oil to the vapor in the chamber 15 tends to vaporize anyremaining liquid particles therein, thereby further precluding deliveryof liquid droplets to the compressor.

As best seen in FIGURE 1, the housing members 12, 13 and 14 are joinedto each other, as by welding, at the lower end 33 ofthe member 12 andupper ends 34 and 35 of the lower members 13 and 14, respectively.Additionally, the outer lower member 13 is provided with a verticallyextending inwardly depressed portion 36 which is welded to the member 14to provide additional rigidity to the structure.

Upper end 35 of inner housing member 14 is provided with a plurality ofsmall openings 37 (herein three openings) providing restrictedcommunication between inlet chamber 15 and suction chamber 24. Therefrigerant vapor passes from chamber 15 through openings 37 to ow overthe motor 17, as shown in FIGURE 1, thereby cooling the motor andproviding improved efficiency of operation thereof. The heat of themotor additionally serves to vaporize remaining liquid entrained in thevapor. Also, the rotating armature tends to provide further separationof remaining liquid for com-plete vaporization.

As best seen in FIGURE 1, front head 18 defines an annular, upwardlyopening trough 38 in which any remaining liquidin the refrigerant vaporcollects prior'to the ow of the vapor to the compressor apparatus. Also,oil collects in this trough, aswill be explained subsequently. As shownin FIGURE 4, the front head 18 is provided with an inlet passage 39-opening downwardly to the compressor chamber 40 in cylinder 19.Cylinder 19 is provided with a vertical passage 41 which communicateswith the inlet passage 39 in front head 18 and with a recess 42 in therear head 21. As shown in FIGURE 4, the recess communicates also wif?.the compressor chamber 40 and thus refrigerant vapor is delivered fromits inlet passage 39 concurrently into the `top and bottom of thechamber 40.

Front head 18 is'further provided with a small passage 43 which meters asmall quantity of the oil collected in trough 38 into the refrigerantvapor being delivered to the compressor chamber 40. Lubricating oilliquid delivered into the refrigerant vapor in this manner serves tolubricate the compressor during the operation thereof.

As best seen in FIGURES 1 and 3, the compressed vapor is delivered fromchamber 40 through an outlet passage 44 in rear head 21 which opens intoa mutiier chamber 45. The compressed vapor passes from chamber 45 to adelivery passage 46 in the rear head 21 opening upwardly into a deliverypassage 47 in the cylinder 19 which, in turn, opens through a deliverypassage 48 in the front head 18 communicating with the high pressurechamber 25. The high pressure chamber 25 thusly sreves as a secondmufiier chamber cooperating with chamber 45 to effectively minimize thesounds produced by the compression of the vapor in the chamber 40.

As shown in FIGURES l and 3, the high pressure compressed refrigerant isdelivered from chamber 25 through an outlet 49 which is connected bysuitable conduit means- (not shown) to the condenser of the compressionsystem (not shown). lA normally closed fitting 50 may be providedcommunicating with chamber 25 for introducing lubricating oil and forcharging the compressor when desired.

The oil 27 in the sump portion 26 of the housing member 14 is under therelatively high pressure of the compressed gas in chamber 25 and isforced thereby through a suitable downwardly opening channel 51, as bestseen in FIGURE 4, in rear head 21 to a central recess 52 in the rearhead into which the lower end of the shaft 22 extends. As shown inFIGURE v4, the shaft is provided with a bore 53 opening at its lower endinto recess 52 and at its upper end radially through the shaft to theannular space 54 between the shaft and the bear` ing surface of thefront head 18. A suita-hle filter screen 55 may be disposed across therecess 52 to filter ythe lubricating oil as it passes upwardly under thecompressed gas pressure through the recess to lubricate the shaft 22 andthe rotor 20 at its upper and lower surfaces 20a and 20b.

As indicated briefiy above, the openings 37 between inlet chamber 15 andsuction chamber 24 are restricted, thus, a pressure differential (eg.approximately l pound per square inch) is produced between thesechambers. As shown in FIGURE 2, one of the screws 56 provided tomaintain the rear head cylinder and front head of the compressorapparatus 16 in assembled relationship may be provided with an axialbore which opens at its lower end `into the chamber 15 and its upper endinto the trough 38 of the upper head 18. Thus, the collected lubricatingoil in the lower portion of chamber 15 is forced, by the pressuredifferential existing between chamber 15 and chamber 24 into whichtrough 38 opens, upwardly through the bore 57 and into the trough. Thisoil is delivered through the passage 43 into the refrigerant vapor beingdelivered to the compressor chamber 4t) as discussed above, therebyfurther assisting in the lubrication of the compressor.

Thus, compressor 10 provides a simple improved structural arrangementwhereby improved cooling of the lubricating oil, removal of entrainedmaterial from the incoming refrigerant vapor, and improved lubricationof the rotating parts of the compressor are provided. TheA operation ofthe compressor is substantially improved as shock loads on the bearingsresulting from liquid in the vapor are effectively eliminated and thenoise normally encountered in such compressors on start up iseffectively eliminated.

While I have shown and described on embodiment of my invention, it is tobe understood that it is capable of many modifications. Changes,therefore, in the construction and arrangement may be made Withoutdeparting from the spirit and scope of the invention as defined in theappended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. Apparatus for compressing refrigerant gas, comprising: first housingmeans defining a pressure space; compressor means in said first housingmeans for compressing said refrigerant gas;v second housing means spacedfrom said first housing means t-o define a passage therebetween; meansdefining a lubricating oil sump in said pressure space; third housingmeans closing said first and second housing means and including achamber in communication with said compressor means; conduit means forconducting said refrigerant gas to said passage; and means forconducting said refrigerant gas from said passage to said chamber forcompression of said gas by said compressor means.

2. Apparatus for compressing refrigerant gas, com prising: first housingmeans defining a pressure space; compressor means in said first housingmeans for compressing said refrigerant gas; second housing means spacedfrom said first housing means to define a passage therebetween; meansdefining a lubricating oil sump in said pressure space; third housingmeans closing said first and second housing means and including achamber 'in communication with said compressor means; conduit means forconducting said refrigerant gas to said passage; and means forconducting said refrigerant gas from said passage to said chamber forcompression of said gas by said compressor means, said lubricating oilsump being in thermal contact with said refrigerant gas flowing throughsaid passage for cooling of said oil sump.

3. Apparatus for compressing refrigerant gas, comprising: a housingdefining a chamber including a p0rtion defining a pressure spaceincluding a lubricating oil sump; means in said chamber for compressingrefrigerant gas; wall means adjacent said sump portion of the housingdefining a passage between said housing portion and wall means; meansfor conducting refrigerant gas to said passage for cooling said sump;and means for conduct- -ing the refrigerant gas from said passage tosaid chamber for compression therein by said compressing means.

4. The apparatus of claim 3 wherein said wall means substantiallysurrounds said sumpportion of the housing.

5. Apparatus for compressing refrigerant gas, comprising: a housingdefining a chamber including a first portion defining a suction spaceand a second portion defining a pressure space including a lubricatingoil sump; means in said chamber and communicating with said suctionspace for compressing refrigerant gas; wall means adjacent said sumpportion of the housing defining a passage between said housing portionand wall means; means for conducting refrigerant gas to said passage forcooling said sump; and means for conducting the refrigerant gas fromsaid passage to said suction space for compression by said compressingmeans, said last-named means being arranged to maintain the gas pressurein said passage substantially higher than in said suction space.

6. The apparatus of claim 5 wherein said last-named refrigerantgasconducting means comprises means defining a flow restricting orificecommunicating with said passage and said suction space.

7. Apparatus for compressing refrigerant gas, comprising: a housingdefining a chamber including a first portion defining a suction spaceand a second portion defining a pressure space including a firstlubricating oil sump; means in said chamber and communicating with saidsuction space for compressing refrigerant gas; wall means adjacent saidfirst sump portion of the housing defining a passage between saidhousing portion and wall means and defining a second lubricating oilsump; means for conducting refrigerant gas to said passage for coolingsaid first sump; and means for conducting the refrigerant gas from saidpassage to said suction space for cornpression by said compressingmeans, said last-named means being arranged to maintain the gas pressurein said passage substantially higher than in said suction space, saidhousing second portion and said wall means being arranged to provide abaflie effect whereby lubricating o il entrained in the refrigerant gasis caused to drop therefrom in said passage and collect in said secondsump.

8. Apparatus for compressing refrigerant gas, comprising: a housingdefining a chamber including a first portion defining a suction spaceand a second portion defining a pressure space including a rstlubricating oil sump; means in said chamber and communicating with saidsuction space for compressing refrigerant gas; wall means adjacent saidfirst sump portion of the housing defining a passage between saidhousing portion and wall means and a second lubricating oil sump; meansfor conducting refrigerant gas to said passage for cooling said firstsump; means for conducting the refrigerant gas from said passage to saidsuction space for compression by said compressing means, said last-namedmeans being arranged to maintain the gas pressure in said ow passagesubstantially higher than in said suction space; and passage means forconducting lubricating oil from said second sump to said suction spaceas a result of the pressure differential therebetween.

9. Apparatus for compressing refrigerant gas, comprising: a housingdefining a chamber including a first portion defining a suction spaceand a second portion CII defining a pressure space including a firstlubricating oil sump; compressor means in said chamber for compressingrefrigerant gas including a front head extending across the chamber anddefining an inlet, a cylinder defining a compression chambercommunicating with said inlet, a rotor in said chamber, and a rear headdisposed in said first sump, and means for conducting compressed gasfrom said compression chamber to said pressure space; means sealing saidfront head to said housing to seal said suction space from said pressurespace; wall means adjacent said first sump portion of the housingdefining a passage between said housing portion and wall means, and asecond lubricating oil sump; means for conducting refrigerant gas tosaid passage for cooling said sump; and means for conducting therefrigerant gas from said passage to said suction space for compressionby said compressing means, said last-named means being arranged tomaintain the gas pressure in said passage substantially higher than insaid suction space.

10. The apparatus of claim 9 including means defining a passage betweensaid second sump and said inlet.

11. The apparatus of claim 9 wherein said compressor means includes abolt extending through said front head, cylinder, and rear head andhaving an axial bore provid- .ing a passage for oil from said secondsump to said suction space adjacent said inlet.

References Cited by the Examiner UNITED STATES PATENTS 1,781,082 11/30-Ruegger 230-139 3,008,629 11/61 Gerteis 230-206 FOREIGN PATENTS1,120,481 12/61 Germany.

LAURENCE V. EFNER, Primary Examiner.

ROBERT M. WALKER, Examiner.

1. APPARATUS FOR COMPRESSING REFRIGERANT GAS, COMPRISING: FIRST HOUSINGMEANS DEFINING A PRESSURE SPACE; COMPRESSOR MEANS IN SAID FIRST HOUSINGMEANS FOR COMPRESSING SAID REFRIGERANT GAS; SECOND HOUSING MEANS SPACEDFROM SAID FIRST HOUSING MEANS TO DEFINE A PASSAGE THEREBETWEEN; MEANSDEFINING A LUBRICATING OIL SUMP IN SAID PRESSURE SPACE; THIRD HOUSINGMEANS CLOSING SAID FIRST AND SECOND HOUSING MEANS AND INCLUDING ACHAMBER IN COMMUNICATION WITH SAID COMPRESSOR MEANS; CONDUIT MEANS FORCONDUCTING SAID REFRIGERANT GAS TO SAID PASSAGE; AND MEANS FORCONDUCTING SAID REFRIGERANT GAS FROM